New Neurologist Says There's No Low Blood Pressure/cerebral Hypoperfusion

[peregrine]

Trying to figure out how to make sense of what happened today. So my awesome autonomic neurologist picked up shop to a place 20 miles north of here that my insurance will only sort-of cover, and referred me to someone I'd seen once before for an unrelated, pre-POTS issue. I saw him today for the first post-POTS time and I'm trying to figure out what's going on. Context - I have my diagnoses, I'm on a beta blocker and pyridostigmine, my main issues are spaciness and presyncope (whoo summer). I planned to ask him about additional options - trialling clonidine, understanding why midodrine isn't for me, etc.

He read my history quickly, talked with me about what had and hadn't worked med-wise (didn't ask about fluids, salt, or compression, other than noting that I was doing all three). He asked why I thought I was spacey, and seemed curious to hear my response (whoo biology education). I said "I'm not sure, cerebral hypoperfusion maybe?" and he replied that he's pretty sure that's not going on, that I don't have low blood pressure when I'm standing (only kind of true?), and that - while there may be some blood vessel-caused localized hypoperfusion, he's pretty sure my brain as a whole is doing just fine when I stand. And that midodrine is totally not the right call, since I don't have low blood pressure. I can't tell if this is my case in particular, or if he's in the "POTS and NMH/low blood pressure in general are mutually exclusive" camp. (note that I don't have NMH, and no low BP when sitting)

The problem with this is that, while my sitting BP fluctuates between 106/64 and 140/85 (new since the POTS onset last year), my BP did fluctuate massively in both directions during my TTT - the highest looks like 170/100 and the lowest was 62/50 (near the end, as my HR topped out at 160 and they lowered me down). And I do get presyncope/lightheadedness, which I thought was associated with/caused by low cerebral blood flow? So I'm not sure what to make of what he said versus the symptoms I have and the TTT results (I don't know how much of the TTT results he read, since he seemed to be reading clinic notes during the appointment and hadn't read them beforehand). Edited to add - my TTT BP values did fluctuate pretty hilariously - about every 10 seconds the systolic went up/down by about 20-25mmHg and the diastolic by about 15mmHg - just swinging back and forth.

We're going to try upping the pyridostigmine to 90mg 3x/day (up from my usual 60mg 3x/day) and then to 120mg 3x/day and see if that helps. After that we're talking about a stimulant (both of us are nervous about it due to the potential for triggering mania), and it sounds like clonidine might still be on the table.

Thoughts? Is he misreading the situation, or did I misunderstand my TTT results?

[HopeSprings]

I think he's making an educated guess, but how can he know for certain what's happening to the blood flow in your brain? Even POTS researchers get conflicting results when they've tried to study this. I'm to the point where I don't think they know anything for sure. Wondering if Midodrine would be a bad choice since you did get very high BP on the tilt test?

[sue1234]

I agree, Naomi, I don't think they really know. I can drink or eat something warm/hot, and for the next hour I am in a brainfog. Just the warmth must vasodilate my upper body/brain and cause pooling. It happens even sitting. I don't drink coffee due to that fact, and I forget when I eat soup and get foggy anyway. Then I remember.

I have often wanted to tell a doctor that if they could measure my head pressure, it would be different than what a b/p cuff on my arm says. Besides what feels like not enough perfusion, I have days that I feel like I have too much. I can just feel the total pressure.

[McBlonde]

Good grief! You are right. These doctors are beyond frustrating and wasting our time and money!! Yes, you will definitely get the pre-syncope issues when your BP drops so drastically like you describe or at least I do. That is a shame that your great doctor moved away. What state did he go to?

[Katybug]

I thought the cerebral perfusion had to do with the blood pooling in our lower extremities and not our BP???? I could be wrong because as everyone has stated, even the POTS researchers aren't 100% sure. But, my understanding is that our BP could be fine but if all the blood is down in our legs and abdomen, then not enough is getting to our brain to fully oxygenate it the way it normally would. NOt, saying we have full perfusion, but enough to affect our cognitive skills to some degree. Although, if you are an unlucky person with both POTS and NMH, I would think the low BP would be the double whammy! Ugh!

[jangle]

What I'd like to tell your doctor is the following.

"In the case of Raynaud's a patient does not necessarily have systemic low blood pressure, yet their feet or hands experiences a hypoperfusion of blood. This is due to vasospasm of the relevant blood vessels. I'm not sure what causes the vasospasm, but because Raynaud's occurs in POTS and POTS is linked with excessive norepinephrine in the neurons, it might be due to excessive norepinephrine. Since norepinephrine can cross the blood brain barrier, it is also exerting effects on the brain. By the same mechanism, it might be causing vasospasm here which throws off the cerebral autoregulation. This is all without significantly affecting systemic blood pressure - just like in Raynauds."

I'd actually be curious as to the response.

Edited July 27, 2012 by corina

[sue1234]

Great analogy, Jangle!

[McBlonde]

I don't know Katie.... Now I'm getting confused! I thought the dysautonomia doctor that I just went to said that my pre-syncope symptoms I had in his office was because my BP feel from 140/95 to 99/70 while standing and that my blood vessels in my brain weren't constricting when my pressure came by up so..... cerebral hypoperfusion. (but I may be 100% wrong)

[jangle]

I don't know Katie.... Now I'm getting confused! I thought the dysautonomia doctor that I just went to said that my pre-syncope symptoms I had in his office was because my BP feel from 140/95 to 99/70 while standing and that my blood vessels in my brain weren't constricting when my pressure came by up so..... cerebral hypoperfusion. (but I may be 100% wrong)

hypotension can also cause hypoperfusion of the brain. I say "also" liberally as I'm not entirely sure norepinephrine can cause vasospasm in the brain similar to Raynauds, but I'm just extrapolating that it can.

[Dizzysillyak]

Great info jangle.

So do we know what causes Raynauds ? Does Raynauds always include

blood flow changes that you can see ? My hands hurt so bad when I try to hold anything

cold but don't change color. But, my feet used to hurt just as much if I walked on cold tile barefoot too but

that's gone now. I'm guessing nerve damage ... Tc .. D

[Katybug]

I don't know for sure either, as I said. All I know is that my BP can be 95/64 lying down and I feel just fine. Then, I stand up and my BP stays the same, my heart rate jumps up, but I feel all the blood drain into my legs and abdomen, and I start to feel dizzy, drunk, uncoordinated, unsure of the timing of my reflexes, and like I couldn't learn anything at that moment if someone had me at knife point. All things I associate with cerebral perfusion. My best guess is that the etiology of this symptom is another thing that varies with a person's particular presentation.

[issie]

I think some of the latest thinking is there is lack of blood flow to anything above heart level. (Put your arms up and try to fix your hair - what happens?) What I'm trying right now - increases blood flow to the brain, it is however also a mild diuretic. But, I'm tolerating it so far and I'm feeling some better. It increases resperation and that increase oxygen - to everything. (The possible side effects are really scary though. Hope I don't get any of them.)

It's Diamox.

Issie

[peregrine]

Thanks for the response, all! For some reason the notifications failed to reach me and I missed all of the awesome replies.

I suspect you guys are right about the midodrine - that it's a bad idea given both the high BP on the TTT and my overall generally higher BPs when measured sitting at the doctor's office. Looking at my metronomic breathing test, I also got up to 140-150 over 75, so probably not the best idea.

Hmm... some of me is now confused. Jangle's analogy helps so much! Thank you! I do know that I can't keep my arms above my head for more than about 30 seconds without feeling really bad, although (unlike some) I can bend over and squat just fine (minus the knee pain). So is the thought that the cerebral autoregulation stuff is not really due to BP but more due to, say, norepinephrine? I wish they'd had a way to measure cerebral blood flow at UW where I got my autonomic testing done.

My autonomic neurologist moved not *too* far away, actually - in the same state, but a 3-hour ride by public transit (I can't drive, though may be able to get my partner to get a Zipcar). Depending on how things go with the new guy, I may switch back to her anyways. Hmm.